modifying columns in the logging database

I am tasked with enhancing and existing n-tier C-Sharp application.
IT Dept would like writeLog to capture user information in addition to what is already captured
The writelog function looks like this:

using System;
using System.Diagnostics;
using Microsoft.Practices.EnterpriseLibrary.Logging;
using System.Configuration;

and is of course a wrapper to the logging libray WRITE function in Microsoft.Practices.EnterpriseLibrary.Logging.
Since to my knowledge I can't change the WRITE function and probably wouldn't want to. How can I pass the user information to the database?